Commutator-turning tool.



J. MOLES. CO'MMUTATOR TURNING. TO0L. APPLICATION FILED JULY 24. !915.

w N d m m P JOHN MOLES, OF ERIE, PENNSYLVANIA, ASSIGNOR '10 THE EUREKACOMPANY, OF NORTH EAST, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

COMMUTATOR-TURNING TOOL.

Specification of Letters Patent.

Patented Nov. 2,- 1915.

Application filed July 24, 1915. ,Serial No. 41,691.

T 0 all whom it may concern:

zen of the United States, residing at Erie, in the county of Erie andState of Penn sylvania, have invented new and useful Improvements inCommutator-Turning Tools, of which the following is a specification.

This invention relates to commutator turning tools and consists incertain improvements in the construction thereof as will be hereinafterfully described and pointed out in the claims.

In the turning of commutator bars it has been the practice to assemblethese bars with insulating material between them in their final annularposition anduto clamp the bars so assembled so that the surfaces of thebars may be turned. The ordinary commutator bars have the insides of thebars turned and are also provided with anchor parts which with the barsassembled form a dove-tail ring .on the inner periphery of thecommutator; Difliculty has been experienced in turning the insides ofthe bars and the beveled surfaces of these anchor parts with rapidity. M

The object of this invention is to accomplish'this purpose in a bettermanner than has been heretofore practised and to provide the tool for soaccomplishing the pur- )OSG.

I The invention is illustrated in the accompanying drawing wherein 1marks the shank of the tool, 2 the tool holder, and 3 a first tool whichis secured to the tool holder by extending into the tool holder andbeing clamped therein by set screws 4.

5 is a second tool extending into the tool holder and being clampedtherein by set screws 6.

7 is a stop for ment of the t'ool tator, this stop holder and beinglimiting the axial moverelatively to the commuextending into the toolclamped therein by a set screw 9. The first 'tool 3 has a cutting edge10 which is adapted to turn the inner surface 11 of the bars 11. Thetool must have a. clearance sufficient to avoid cutting the face of theanchor part 13 because if the rear of the back edge of the tool engagesthe face of the anchor pieces 13.

This tool should have clearance enough to avoid cutting the surface 11so that the accuracy of the cutting device 12 is not interfered with. Inthis way the two surfaces, the face of the anchor parts and the surface11 may be cut with great rapidity and with great accuracy. The sharpgroove such as is formed by the commutator bars between the innersurface of the commutator and the anchor pieces presents greatdilficiilty even where the material turned is solid but where there is avariation as in commutator bars andtheir insulating material thedifficulty precludes ordinary methods and the operation has beenheretofore very slow.

A tool 14- is carried by an extension 15 on the shank 1 and secured inplace by the set screws 16. This is designed to operate in advance ofthe tools 3 and 5 and to turn the inner' surfaces of the anchor parts.

It will be readily observed that the ends of the tools 3 and 5 arepractically in a plane at right angles to the axis of the tool. This isnecessary in order that, the tool 5 may be utilized only for cutting thesurfaces of the anchor parts and the tool 3 fo the inner surfaces of thebars. I

.What I claim as new is 1. In a commutator turning tool, the combinationof a shank; andcutting tools carried by the shank, the first of saidtools hav ing a. cutting edge extending in an axial.

second of said tools having a cutting edge extending on a slant to theaxis of the tool to'form the face of the anchor part of the bars andhaving a clearance to avoid cut ting the inner surface of the bars, theends of said tools being in a plane at right angles to the axis.

:2. In a commutator turning tool, the com- I bination of a shank;cutting tools carried by the shank, the first of said tools having acutting edge extending in an axial direction to turn the inner surfacesof assembled commutator bars, the end of said first tool having aclearance to avoid cutting the anchor part of such bars, and the secondof said tools having a cuttingedge extend- 'ing on a slant to the axisof the tool to form the face of the anchor part of the bars and Intestimony whereof I have hereunto set havln e clearance to avoid euttnithe inmy hand in the presence 01' two subscribing ner surface of thebars, the ends of said witnesses. tools being in apiane at' right anglesto JOHN MOLES. the axis; and a third tool in advance of the Witnesses:

first and second tools for turning the inner B. M. HAn'rMAN, surface ofthe anchor part of the bars.

THOMAS C. MILLER.

